Investigation of the mechanism of gelatin to enhance 3D printing accuracy of corn starch gel: From perspective of phase morphological changes

The study examined the impact of phase morphological transformations within the corn starch/gelatin system, induced by varying gelatin content, on its rheological properties and 3D printing performance. Gelatin addition inhibited the gelatinization and retrogradation of starch, which leaded to the transformation of continuous phase structure. The transition process from starch continuous phase to gelatin continuous phase promoted a thinner wall structure of the gel and loosed its dense network, resulting in reduced flow stress (τf) and storage modulus (G′). These changes improved the extrusion and “extrusion swelling" of gel ink materials, which made the print size of printed product closer to the set model. The formation of a gelatin continuous phase in the gel was helpful in increasing τf and G′, resulting in enhanced support capacity of the printed product. This study presented meaningful information for the application of 3D printing to starch-gelatin complex foods.